JohnMo

Thanks for that will discuss with the electrician. He said he has installed the Givenergy all in one before and is a registered installer, but I am the first to ask for a gateway. So he is off to do the online training course.

. You have a body of water in the cylinder it is static. The heat pump cylinder has a 20.1m long 20mm coil from bottom to top of cylinder of heating - coil is twice as long as their normal cylinder. There is a second coil for heating DHW from bottom to top of cylinder again 20mm dia but about 10m long The immersion heater and thermostat are accessed from top of cylinder. Cold in and hot out are at top of cylinder, as is the cylinder filling loop. There is also a mixing valve set to temper water temp. Not a lot different from a thermal store Overflow you can overflow to catch tank or to a drain in case of overfilling

Also heat pump package would have to be immersion free, nothing in the buffer, low loss header or the heat pump it's self. How do you legislate for all this. What happen in 10 years if the HP come along that boils water, throw all the old heat pump cylinders away, because they are not G3 complaint. Sorry you are dreaming and not being realistic. If you don't want G3, go vented or a solution such a Harlequin cylinder or thermal store.

Lots of if and buts. Some HP can achieve the required temp for pasteurization, many cannot. How many immersion less cylinders have you ever come across installed or being sold? If there any they are exception rather than the rule. The cylinder would have to have zero provision for an immersion and happens if someone later decides to strap a willis heater on the side? Wishful thinking that G3 doesn't need to apply.

That is only true without an immersion heater. Not seen any cylinders without an immersion as a heat pump cylinder is fitted with them for legionella...

This where you need to get decent data. https://www.eurovent-certification.com/ Note if the unit is made by company A and supplied to company B C D etc to put there own name plate on it, then the data is for company A (the original manufacturer).

Exactly Been in the air force and oil and gas industry, but went to a big electrical suppliers factory, fire alarm went off (not a practice) everyone just sat there, until they smelt the smoke - real fire. One one injured but was taken aback by the piss poor attitude.

If you had a bad fire wouldn't RCD just trip?

I applied for non MCS scheme on Friday will see how it goes. Cut and paste the T&C's in to the email, used my G98 commissioning cert and used the words in the T&C's to declare I was happy with the install...

That is pretty much what RED do, they use a Harlequin cylinder, 1.2m2 heating coil and a big DHW coil, the cylinder is vented, the water in the cylinder just stays there to carry heat like a thermal store

I enjoyed thermodynamics at HNC level and at degree level until the exam. Completely messed up the exam at degree level. So was dropped after that.

Thanks @sharpener for questions prompting me to think about different things and ask the right questions.

Just spoke with the electrician and if I want the whole house in a power outage it would have to be via a manual change over switch. Which isn't really what I wanted. So we are now going Givenergy all-in-one with gateway. The only limitation is inverter doesn't like generators, so once battery depleted and I start the generator the grid / generator change over switch will disconnect the battery/inverter as well as the grid. He said I need an additional earth spike. More money, but bigger battery, less faff.

From what I can tell you wire so it will give the 5kW output in an outage or you can use dedicated EPS function, for a few circuits. But have just sent an email asking the question

Our dishwasher takes hot water, but it only really works if the dishwasher goes on as soon as you have finished using the hot tap. Otherwise the water draw is too small to get hot water in to the dishwasher. 50% compared to what and when

If you only intend to have 100mm insulation in total, I would keep my money in my pocket, by not doing UFH. The downward heat loss will empty your pockets for ever more. Your heat loss downwards is based on UFH flow temp and the ground temp. So say 36 deg flow temp and 6 deg ground temp., So you have a delta of 30 deg. If you had radiators the room temp and ground is used to find the delta T, so 21 - 6 is 15. Heat loss is based on the floor U value multiplied area, multiplied by delta T. So everything else being equal, the downwards heat loss is double with UFH compared to radiators, because the delta T is double with UFH compared to radiators.

I still think your choice of heat pump is overkill. Looking at your SAP and compared to mine. Your Jan heat loss is 2388W, mine with the same average temp is 2979W. But at -9 Outside, our heating system draws 3.5kW - This being measured by a certified heat meter and tying in exactly with gas consumption (gas boiler at that time). When the heat season starts and most of the winter you are pulling just under to just over 1kW. Extreme days are not the norm. If you look at your graph and extent the lines left to the 1 to 3kW area things start to look very different. Both the Samsung and Midea are falling in efficiency.

Manifold looks like this, main stop cock at lower right corner, to the left is the pipe and isolator outside tap, bigger white pipe takes water up to plant room

I kept it simple just 15mm everywhere. Image of shower room, no bath in this room. Hot water pipes come from cieling cold out of floor. Two curved vertical pipes are to shower.

It all becomes very simple, no hidden joints, single run between manifold and each location. Once in the room I split down with tees to bath, shower, sink and toilet. Smaller than 22mm which the plumber may use as a header, big enough to supply the bath with good etc. Basically a secondary pipe in the hot water system. A pump, timer and thermostat, takes hot water from cylinder and pushes it around the domestic hot water system, so the pipe and water is hot prior to the water coming out of the tap. Our furthest tap is 18m from the cylinder, we have the pump on in the morning and evening, within a second or so, warm water comes out of the tap. Costs almost nothing to run so long as it's only running when you need it on.

6. A robot that cleans our gutters every six months would good. But I could always just pay someone for that, or do it myself as I do now

Would agree, also smart i.e. internet connected thermostats, hot water cylinder, why bother. Support or technology likely to leave the item behind, (not supported or operable) long before it breaks.

A2W also unserviceable, if they break.

https://www.gbnews.com/news/british-gas-hive-security-system-discontinued What gets pulled next. It's smart until the seller or manufacturer pulls the plug.

Or possibly the "real world" this is the real solution to the mass roll out of heat pumps. Easy to install, not expensive, no piss poor CoP to worry about. Competitive price wise with a normal boiler. Issue is general public perception, they think Aircon, expensive to run and cooling only.